The present invention relates to a plate inserting apparatus for inserting the leading edge bent portion of a new plate into the groove portion of a plate cylinder.
As described in U.S. Pre-Grant Publication No. 2007/0006759, a conventional plate inserting apparatus includes a press roller which is rotatably supported to be able to come close to and separate from the outer surface of a plate cylinder and which inserts the leading edge bent portion of a new plate into a groove portion formed in the outer surface of the plate cylinder, an air cylinder which presses the press roller against the outer surface of the plate cylinder, and a switch provided to the air cylinder. When the leading edge bent portion of a new plate cannot be inserted in the groove portion of the plate cylinder and the new plate floats from the outer surface of the plate cylinder, the switch detects this abnormality.
In the conventional plate inserting apparatus described above, the switch detects the abnormality that the leading edge bent portion of the new plate cannot be inserted in the groove portion of the plate cylinder. The leading edge bent portion that cannot be inserted in the groove portion may, however, undesirably be caught between the plate cylinder and press roller and be crushed. The new plate with the crushed leading edge bent portion can no longer be used, which is uneconomical. Also, another new plate must be remounted in a plate changing device, leading to poor working efficiency.